JavaScript For Loop of

Loops can execute a block of code as long as a specified condition is true.

The While Loop

The while loop loops through a block of code as long as a specified condition is true

Example

   <!DOCTYPE html>
 <html>
  <body>
 <h2>JavaScript While Loop</h2>
  <p id="demo"></p>
<script>
// Initialize an empty string 'text'
 let text = "";
// Initialize a variable 'i' with the value 0
 let i = 0;
// While loop that iterates while 'i' is less than 10
 while (i < 10) {
 // Concatenate the current value of 'i' to the 'text' string
 text += "<br>The number is " + i;
 // Increment the value of 'i'
 i++;
 }
// Display the result in the paragraph with id "demo"
 document.getElementById("demo").innerHTML = text;
 </script>

 </body>
 </html>

You can click on above box to edit the code and run again.

Output

The Do While Loop

The do while loop is a variant of the while loop. This loop will execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true.

Example

  do {
  // code block to be executed
 }
while (condition);

Example

 <!DOCTYPE html>
  <html>
  <body>

 <h2>JavaScript Do While Loop</h2>

<p id="demo"></p>

 <script>
// Initialize an empty string 'text'
let text = "";

// Initialize a variable 'i' with the value 0
let i = 0;

// Do...while loop that iterates at least once and continues while 'i' is less than 10
 do {
// Concatenate the current value of 'i' to the 'text' string
  text += "<br>The number is " + i;

// Increment the value of 'i'
 i++;
} while (i < 10);


// Display the result in the paragraph with id "demo"
document.getElementById("demo").innerHTML = text;

  </script>

      </body> 
      </html>

You can click on above box to edit the code and run again.